Egypt and farming.

 Egypt is a dry desert area. It was only thanks to the Nile that farming was possible in the desert. Without the Nile River, neither Egypt nor splendid Egyptian civilization would have blossomed. That's why Egypt is called the Gift of the Nile River.

  The downstream of the Nile River floods at a certain time every year. Due to the rain falling in the upper part of the Nile River, the water in the middle and downstream areas gradually increases, causing floods in the downstream areas. So, they supplied water to dry areas without much damage. Farmers only had to sow seeds on the ground where the water had escaped. Then the greasy soil from the upper stream supplied nutrients, and the Nile River supplied water to grow crops. For this reason, people began to live together in the Nile basin early on, and a country called Egypt could be created.

  Egyptians made calendars (solar power) to predict flooding of the Nile River, and developed surveying, geometry, and mathematics for land surveying or civil engineering.